Portland Cement Reconsideration 

Technical Support Document

DRAFT

May 2012
ii

Table of Contents

1. Introduction..........................................................................................................................1

2. Outdoor Clinker Storage Pile Work Practice Standard Development.................................1

2.1 Control Measure Results......................................................................................... 2

2.2 Emission Standard Results...................................................................................... 3

3. Continuously Monitored Parameters for Alternative Organic HAP Standard (with 

THC Monitoring Parameter)................................................................................................4

4. Coal Mills.............................................................................................................................5

5. PM Standard for Modified Sources Under the NSPS........................................................11

6. Alternative PM Limit.........................................................................................................11

7. MACT Floor Development................................................................................................12

7.1 Hydrogen Chloride (HCl) ..................................................................................... 13

7.2 Mercury (Hg) ........................................................................................................ 14

7.3 Particulate Matter (PM) ........................................................................................ 15

7.4 Total Hydrocarbon (THC) .................................................................................... 15

7.5 Organic HAP (oHAP)........................................................................................... 16

8. Impacts of Revised PM Standard.......................................................................................16

9. Summary............................................................................................................................18

List of Tables

Table 1: Summary of 2012 Proposed NESHAP for Existing Sources......................................... 13

Table 2: Summary of 2012 Proposed NESHAP for New Sources............................................... 13
1

1. Introduction 

In response to two separate events, the EPA is proposing amendments to the National Emission 

Standards for Hazardous Air Pollutants (NESHAP) for the Portland cement industry (40 CFR 

part 63 subpart LLL) and to the New Source Performance Standards (NSPS) for Portland cement 

plants (40 CFR part 60 subpart F) issued under the Clean Air Act (CAA). 

In response to industry petitions for administrative reconsideration to reconsider the NESHAP 

standards and specific issues in the NESHAP, and to reconsider the NSPS PM standards, the 

EPA granted reconsideration of portions of the reconsideration petitions on May 17, 2011 (76 FR 

28318). The issues in the NESHAP on which EPA granted reconsideration include: amendments 

to address the regulation of fugitive emissions from open clinker piles, organic hazardous air 

pollutant (HAP) compliance demonstration, applicability of standards to coal mills, requirements 

for monitoring hydrochloric acid (HCl) when controlled using dry scrubbers, , the equations used 

to calculate the PM limits, the affirmative defense for malfunctions and specific issues relating to 

startup, shutdown and malfunction standards. EPA also granted reconsideration of the new 

source performance standards for particulate matter (PM) emissions from modified sources. 

The proposed amendments also respond to the D.C. Circuit’s opinion in Portland Cement Ass’n 

v. EPA, 665 F. 3d 177 (D.C. Cir. 2011). In that case, the court rejected all challenges to the 

methodology EPA used to establish the NESHAP but remanded the NESHAP so that EPA could 

account for the effects of EPA’s Non-Hazardous Secondary Materials (NHSM) rule. 

EPA is proposing to amend the NESHAP new and existing source standards for PM, and to 

make corresponding amendments to the NSPS for PM. EPA is also proposing to amend the 

alternative organic HAP limit in the NESHAP, and to propose amendments regarding many of 

the issues listed above. In addition, we are proposing corrections and clarifications to the rule’s 

testing and monitoring provisions. Because the proposed changes in the PM limits could affect 

compliance strategies for some sources, EPA is proposing to extend the date for compliance with 

the existing source NESHAP to September 9, 2015, two years from the presently applicable 

compliance date.

This Technical Support Document contains pertinent data, calculations, and discussions

regarding new emissions and work practice standards reflected in the proposal. For purposes of 

estimating cost and environmental impacts of the proposed amendments, the data used in

estimating the impacts of the 2010 final rule were used with the exception that 23 kilns (13 

facilities) burning commercial and industrial solid waste (CISWI kilns) were excluded. The 

modified data set consist of 117 existing kilns and 16 new kilns at 87 plants

2. Outdoor Clinker Storage Pile Work Practice Standard Development 

The Portland Cement Association (PCA) has stated that most Title V permits contain provisions 

that reduced fugitive emissions from open clinker piles. To confirm this and to gather 

information on the types of measures required for outdoor storage piles, EPA reviewed 88 

portland cement manufacturing facilities’ permits. Permits were first reviewed to confirm the 

existence of outdoor clinker storage piles and to identify the permit conditions addressing air 

emissions from these storage piles. EPA also examined these permits for provisions regarding 

analogous types of piles, such as those for feed materials. Finally, EPA reviewed permits to 
2

identify any facility-wide permit conditions relating to fugitive dust, visible emissions or opacity

requirements. It was assumed that facility wide conditions apply to any outdoor storage piles, 

unless the permit stated otherwise.

For the purposes of this review, “control measures” were considered to be permit provisions 

requiring the facility to implement some physical measure to control emissions relating to 

outdoor storage piles. Examples of control measures include:

 Requirements for:

o application of asphalt, oil, water, or other suitable chemicals

o full or partial enclosure

o wind barriers

o moisture content 

o silt content

o coverings

o traffic on and around storage pile(s)

o earthen berm and biological wind break

“Emission standards” were broken into three sub-categories, as follows:

 General duty requirements – any general requirement for the facility to “prevent” fugitive 

dust / particulate emissions. 

o Example: The Permittee shall not cause, allow, or permit organic or inorganic dust 

producing material to be stacked, piled, or otherwise stored without taking reasonable 

precautions to prevent excessive amounts of particulate matter from becoming 

airborne.

 Visible emissions limitation – any requirement requiring the facility not to allow visible 

emissions or fugitive dust / particulate to leave the “facility property line.”

o Example: Emissions of fugitive dust from any transport, handling, construction or 

storage activity at this facility shall not be visible in the atmosphere beyond the 

property line of the facility.

o Example: The permittee shall maintain plant roads and grounds in the vicinity of the 

source permitted herein in the following manner so that dust will not leave the 

permittee’s property

 Opacity limitations – any requirement specifying a numerical opacity limit not to be 

exceeded.

o Example: Opacity of an emission from any fugitive dust source shall not be greater 

than 40% measured in accordance with EPA Reference Method 9. 

2.1 Control Measure Results

The detailed results of the control measures review are presented in Appendix I. A summary of 

the results is presented below:

 Outdoor clinker storage piles – 7 permits contained a specific control measure 
3

 Outdoor storage piles – 16 permits contained a specific control measure 

 Facility-wide permit conditions – 31 permits contained a facility-wide control measure.

2.2 Emission Standard Results

The detailed results of the emission standards review are presented in Appendix J. A summary 

of the results is presented below:

 Outdoor clinker storage piles – 8 permits contained specific emission standards. The 

division of requirements is presented below:

Outdoor Clinker Storage Piles

General duty requirements Visible emissions limitation Opacity limitations

1 1 6

 Outdoor storage piles – 18 permits contained specific emission standards. Please note that 

one facility had more than one type (example: general duty and opacity) of requirement. 

The division of requirements is presented below:

Outdoor Storage Piles

General duty requirements Visible emissions limitation Opacity limitations

6 2 12

 Facility-wide permit conditions – 77 permits contained facility-wide emission standards. 

Please note that many facilities had more than one type (example: general duty and 

opacity) of requirement. The division of requirements is presented below:

Facility-wide Permit Conditions

General duty requirements Visible emissions limitation Opacity limitations

27 31 59

Of the 88 permits reviewed in this analysis, 87 had either a control measure or an emission 

standard (i.e., general duty requirement, visible emission limit, or opacity limit) relating to 

fugitive dust / particulate matter control from outdoor storage (assuming that facility-wide 

conditions pertain to outdoor piles). The permit reviewed for one Ohio facility appeared to lack

control measures or emissions standards.

It is important to note that the state of Ohio does have fugitive dust and opacity standards 

relating to fugitive emissions from storage piles (refer to rule 3745-17-07(B) and 3745-17-

08(B)). However these standards only apply to facilities located within certain designated areas 

of the state. For example, the other facility in Ohio evaluated under this analysis has portions of 

its operations located in an area required to implement these standards.

In conclusion, it appears nearly all facilities evaluated have some sort of standard relating to 

fugitive dust from storage piles. However, for general duty requirements it is difficult to 

determine the extent to which a facility has actually complied with “preventative” measures. 
4

Additionally, facility-wide requirements were generally assumed to apply to any outdoor storage 

piles, unless stated otherwise. Facility-wide requirements are required by state rules and 

regulations, which vary state to state. Therefore, there is inherent uncertainty regarding the 

intent of each state regulation and if/how it would apply to storage piles. Although the degree to 

which any of the work practices successfully prevent fugitive emissions will vary, if applied 

properly various sources report emission reductions of 75 to over 90 percent (Western Regional 

Air Partnership Fugitive Dust Handbook, September 7, 2006; USEPA, Technical Background 

Document on Control of Fugitive Dust at Cement Manufacturing Facilities, 1998). These work 

practices have also been identified and are promoted by air pollution control agencies as 

effective fugitive dust control measures (Pima County Department of Environmental Quality, 

Dust Control Measures, 

http://www.deq.pima.gov/air/pdf/DustBrochures/Dust_Methods_Constr.PDF; City of 

Albuquerque Environmental Health Department, Air Quality Division, Fugitive Dust Control, 

12//05, http://www.cabq.gov/airquality/pdf/dustcontrolmethods.pdf).

3. Continuously Monitored Parameters for Alternative Organic HAP 

Standard (with THC Monitoring Parameter)

EPA is proposing a revision to the alternative organic HAP limit from the 2010 rule’s 9 ppm to 

12 ppm based on the method detection capabilities for Method 320 and Method 18, the two 

methods appropriate for the compounds measured when determining compliance with the 

alternative organic HAP limit. For the total organic HAP emissions data, we applied the 

following procedure for determining an RDL for methods used in measuring organic HAPs. We 

determined method detection capabilities for Method 320 and Method 18 as appropriate for the 

various compounds (e.g., Method 320 for aldehydes, Method 18 for arenes). We believe that this 

approach is representative of procedures practiced by the better performing testing companies 

and laboratories using the reasonably applicable and sensitive analytical procedures. We 

determined for each of the organic HAPs the expected method detection level for the respective 

method based on internal experience and method capabilities reported by testing companies. 

With these reported values, we identified the resulting mean of the method detection levels as the 

representative detection level (RDL) because it is characteristic of accepted source emissions 

measurement performance. The following table summarizes those findings.

Pollutant Method used

RDL

ppmv, as measured

RDL

ppmv @7% O2 dry

Formaldehyde Method 320 0.15 0.23

Acetaldehyde “ 1.50 2.34

Benzene Method 18 (adsorbent tube) 0.04 0.08

Toluene “ 0.04 0.08

Styrene “ 0.04 0.08

Xylenes (m,p,o) “ 0.12 0.24

Napthalene “ 0.03 0.06

The second step in the process is to calculate 3xRDL for the sum or total of the organic HAPs to 

compare with the emissions limit in the final rule. This step is similar to calculation of a practical 
5

quantitation limit in other NESHAP including the 2010 final portland cement NESHAP. See 75 

FR at 54984. We use the multiplication factor of 3 to reduce the imprecision of the analytical 

method until the imprecision in the field sampling reflects the relative method precision as 

estimated by the ASME ReMAP study. That study indicates that such relative imprecision 

remains a constant 10 to 20 percent over the range of the method. For assessing a potential 

standard relative to measurement method capabilities, if 3xRDL were less than the candidate 

standard, we would conclude that the standard can be reliably measured. . If, on the other hand, 

the value equal to 3xRDL were greater than the standard, we would conclude that the calculated 

standard could not be measured reliably (or, put another way, failed to account adequately for 

measurement variability). Where such was the case, we increase the calculated standard level to 

the value equal to 3xRDL. This would result in a standard where the method would produce 

measurement accuracy on the order of 10 to 20 percent, similar to other EPA test methods and 

the results found in the ASME ReMAP study.

We summed the RDLs adjusted for dilution and moisture as shown in the table above. We 

determined 3xRDL for the sum of the adjusted pollutants to be 11.2 ppmv @ 7 percent O2, dry. 

This value is greater than the final 9 ppmv @ 7 percent O2, dry, in the final rule. As a result, we 

are proposing to adjust the total organic HAP limit to 12 ppmv @ 7 percent O2, dry. At this 

level, we believe that currently available emissions testing procedures and technologies provide 

the measurement certainty sufficient for sources to reliably demonstrate compliance. Section 

10.5 below contains additional information regarding derivation of the relevant RDLs.

4. Coal Mills 

Cement kilns burn coal as their main fuel, and mill the coal before firing it. From the standpoint 

of air emissions, these coal mills are sometimes physically distinct from the cement kiln, 

generating emissions solely attributable to the coal mill and emitting exhaust through a dedicated 

stack. However, some kilns are configured so that coal mill emissions are commingled with kiln 

exhaust and the emissions are discharged through the main kiln stack. Finally, there are some

configurations whereby kiln emissions are routed to the coal mill and discharged through the 

coal mill stack.

First, EPA has promulgated new source performance standards (40 CFR Part 60 subpart Y) for 

coal mills. See 74 FR 51952 (October 8, 2009). These standards apply to coal mills, including 

coal mills at cement manufacturing facilities, which emit through a dedicated stack. These 

standards do not apply to coal mills at cement facilities whose only heat source is kiln exhaust. 

See section 60.251 (definition of indirect thermal dryer). This leaves at least partially ambiguous 

the regulatory treatment of the situations where a kiln whose coal emissions are discharged 

through the main kiln stack, and the coal mill whose emissions which receives some exhaust 

from the cement kiln so that some portion of the coal mill exhaust reflect cement kiln emissions. 

Because we did not address these issues in the 2010 final NESHAP for portland cement kilns, we 

granted reconsideration in order to do so. See 76 FR at 28326.

A cement kiln which commingles emissions from its coal mill with all other emissions and 

discharges through kiln emission points would have to meet all of the NESHAP. In the case of 

PM, the additional flow from the coal mill would be accounted for in the equation used to 

determine an alternate PM limit from commingled flows. See section 7 below.
6

In the case of a coal mill which receives and discharges some of the cement kiln exhaust, the 

regulatory concern is that this re-routing of kiln exhaust not become a means of avoiding the 

NESHAP controls for cement kiln HAP. 

Our basic principle for this situation would be that the kiln demonstrate that it is meeting all of 

the NESHAP standards for pollutants not regulated under the subpart Y coal mill standard, that is 

mercury, THC, and HCl. Because the subpart Y standards contain a PM standard predicated on 

use of fabric filter control technology, we do not believe it necessary to account for diverted PM 

emissions. 

We are proposing the following compliance mechanisms for the mercury, THC, and HCl 

standards in this situation. 

We are proposing that the sum of the kiln emissions and diverted kiln emissions (i.e. the kiln 

exhaust diverted to the coal mill) must not exceed the subpart LLL NESHAP emission limits for 

each respective HAP or HAP surrogate. The proposed rule contains requirements to document 

the contribution of the emissions diverted to the coal mill. With respect to THC and HCl, 

because coal may be a source of these emissions, we are proposing that performance tests for 

THC and HCl be performed upstream of the coal mill. For mercury, tests would be required 

downstream to account for any mercury removal in the coal mill air pollution control device 

(APCD), and to avoid double counting emissions of mercury from mercury that becomes reentrained in the coal which is then burned by the cement kiln (which emissions are otherwise 

accounted for in the NESHAP). 

An analogous situation is when a cement kiln has an alkali bypass which receives and exhausts 

emissions from the kiln. We are proposing that these emissions be subject to the same 

principle – the total emissions of the kiln and alkali bypass must meet the subpart LLL 

NESHAP – and would use the same monitoring procedures to document compliance. The one 

(slight) exception is PM. Because there is no independent PM standard for an alkali bypass 

(unlike the situation for coal mills, where subpart Y regulates PM emissions), the summed PM 

emissions from the kiln and alkali bypass would have to be equal to or less than the PM limit in 

the subpart LLL NESHAP. Tests for PM from the alkali bypass would be downstream of the 

alkali bypass APCD to account for those emission reductions. 

a. Mercury. Although mercury from the main stack is monitored using a CEMS, there 

is no need for such monitoring for the gas streams from the coal mill. The gas stream to the coal 

mill is small in comparison to the kiln exhaust, operation of the coal mill is intermittent, and the 

cost of requiring additional CEMS for coal mills would be overly burdensome. Instead, we are 

proposing that performance tests for mercury be conducted at such a coal mill once per year, and, 

as explained above, that the tests be conducted downstream of the coal mill. The proposed 

amendments require performance tests for mercury to be conducted using either Methods 29 or 

30B in Appendix A-8 to 40 CFR Part 60. These performance tests would be required annually 

until the tested mercury levels are below the method detection limits for two consecutive years, 

after which tests may be conducted every 30 months. If test results at any time exceed the 

method detection limit, annual performance testing would again be required until mercury levels 

are below the method detection limit for two consecutive years. The results of the performance 

test would then be summed with the emissions from the kiln stack to determine compliance with 
7

the mercury emissions limit. Since kiln stack emissions are measured continuously with a 

CEMS, the coal gas emissions would need to be normalized on both a CEMS and production 

basis (lb/MM ton clinker) in order to be summed with the kiln stack emissions. To do so, we are 

proposing that the flow rate to the coal mill be continuously monitored. Using the results of the 

annual performance test and the flow rate, the owner or operator would develop a mercury

hourly mass emission rate for the coal mill. Using the hourly mass emissions rate and continuous 

flow rate, hourly mercury emissions from the coal mill could be determined and summed with 

the mercury emissions from the kiln to determine continuous compliance (the same approach 

would be applied to a kiln with an alkali bypass that exhausts to a separate stack):

((Qab×Cab)+(Qcm×Ccm)+(Qks×Cks))/P ≤ MACT Limit

Where:

Qab = Alkali bypass flow rate (volume/hr)

Cab = Alkali bypass concentration (lb/dscf)

Qcm = Coal mill flow rate (volume /hr)

Ccm = Coal mill concentration (lb/dscf)

Qks = Kiln stack flow rate (volume /hr)

Cks = Kiln stack concentration (lb/dscf)

P = Kiln production rate (million tons clinker/hr)

MACT Limit = Limit for mercury (55 lb mercury/MM tons clinker)

Thus, if the normalized test results at the coal mill control device outlet shows mercury

emissions of 10 lb/MM tons clinker, emissions from the kiln would have to be less than 45 

lb/MM tons of clinker to be in compliance with the proposed mercury emissions limit.

For kilns also equipped with an alkali bypass, the same procedure as that for the coal mill would 

apply. Where a portion of kiln gases are diverted to a coal mill and to an alkali bypass, emissions 

from the coal mill and alkali bypass would be tested, normalized, and summed and with the 

mercury emissions from the kiln to determine compliance with the emissions limit.

As stated above, the proposed amendments require performance tests for mercury to be 

conducted using either Methods 29 or 30B in Appendix A-8 to 40 CFR Part 60. A cost of a 

single test would be $22,800 per year per kiln and $45,600 if tests are done on the coal mill and 

alkali bypass. The number of sources with separate stacks that would have to be tested is not 

known. If it is assumed that one-half of the 133 kilns (67 kilns) would require test on both the 

coal mill and alkali bypass, total nationwide cost would be $3.1 million per year (45600*67). 

The capital cost of a single flow meter would be $35,780 and $71,560 if installed on the coal mill 

and alkali bypass stacks. Annualized cost for a single flow meter is $11,275 and $22,550 for two. 

Nationwide, the capital cost of flow meters would be $4.8 million (71560*67) with annualized 

cost of $1.5 million (22550*67).
8

b. THC and HCl. Because THC and HCl are concentration-based limits, the proposed 

compliance demonstration differs in certain details from the procedure described above for the 

production based limits for mercury. We are proposing that kiln stack emission limits (to be 

continuously monitored) be calculated taking into consideration the volumetric exhaust gas flow 

rates and concentrations of all applicable effluent streams (kiln stack, coal mill, and alkali 

bypass) for the kiln unit as follows: 

((Qab×Cab)+(Qcm×Ccm)+(Qks×Cks))/((Qab+ Qcm+Qks) )≤MACT Limit

Where:

Qab = Alkali bypass flow rate (volume/hr)

Cab = Alkali bypass concentration (ppmvd)

Qcm = Coal mill flow rate (volume /hr)

Ccm = Coal mill concentration (ppmvd)

Qks = Kiln stack flow rate (volume /hr)

Cks = Kiln stack concentration (ppmvd)

MACT Limit = Limit for THC or HCl (ppmvd)

This equation requires all values to be at or corrected to 7 % oxygen. 

In order to determine the flow rates and concentrations of THC and HCl in the coal mill and 

alkali bypass streams, the source would need to test annually using the appropriate test method 

and would need to monitor the flow rate of the kiln stack with CEMS. For HCl, the performance 

test would be performed using Method 321 in Appendix A to 40 CFR Part 63. For measurement 

of THC, Method 25A in Appendix A-7 to 40 CFR Part 60 would be required. With these data, 

the concentration of THC and HCl that must be monitored in the CEMS in order to demonstrate 

compliance with the MACT limit under this proposal can be calculated by solving for Cks (kiln 

stack concentration) from the equation above, as shown: Cks≤((MACT 

Limit×(Qab+Qcm+Qks))-(Qab×Cab)-(Qcm×Ccm))/Qks

This equation is based on the following: 

 The total allowable mass emissions of THC and HCl for the kiln unit can be determined 

with the sum of all flow rates (coal mill, alkali bypass, and kiln stack) and the applicable 

MACT limit (THC or HCl) concentration. This yields the total allowable mass emissions 

per unit of time for the kiln unit according to the MACT limits and the site specific flow 

rates for the coal mill, alkali bypass, and kiln stack.

 By testing the coal mill and alkali bypass streams for concentration and flow rate, the 

actual mass of THC and HCl emitted per unit of time can be determined.

 Subtracting the actual mass emissions of THC and HCl leaving the coal mill and alkali by

pass from the total allowable mass emissions for the kiln unit determines the remainder of 

allowable mass emissions that can be emitted through the kiln stack.
9

 With knowledge of the flow rate at the kiln stack (measured by CEMS) and the allowable 

mass emissions (i.e. remainder) that can be emitted through the kiln stack, a site specific 

concentration can be determined. The equation above provides a simplified approach to 

determining this value. 

As an illustration of how the site specific limit would be calculated, we have provided the 

following example for calculating a site specific THC emission limit. In this example, we assume 

a kiln stack, coal mill and alkali bypass with the following volumetric flow rates and THC 

concentrations:

Effluent

Stream

Flow Rate

(dscm/hr)

THC 

Concentration

(ppmvd)

(@ 7% O2) Notes

MACT 

LIMIT

(ppmvd)

(@ 7% O2)

Alkali 

Bypass Qab 38,233 Cab 56

Determined through 

test

24 Coal Mill Qcm 57,349 Ccm 56

Determined through 

test

Kiln Stack Qks 286,746 Cks TBD

Flow rate monitored 

by CEMS

With the simplified equation provided above, the THC value that must not be exceeded in the 

kiln stack (verified with CEMS) is determined as follows: 

Cks≤((3024×(38,233+57,349+286,746))-(38,233×56)-(57,349×56))/286,746

Using the equation above, Cks is less than or equal to 13.3 ppmvd @ 7% O2. This site specific 

value would be monitored by a CEMS in order to demonstrate compliance with the 24 ppmvd 

MACT limit for THC. 

The proposal for THC and HCl is thus essentially the same as that for mercury (except that 

concentrations are involved rather than production-normalized mass): the flow-weighted 

averages of THC and HCl must be less than or equal to the subpart LLL NESHAP. The kiln 

stack emissions are measured by a CEMS (for THC) or by other applicable means (for HCl). 

The flow-weighted contributions from other sources (the alkali bypass and the kiln exhaust 

diverted to the coal mill) are assessed by annual testing and applied continuously with flow being 

measured continuously (explained further in the next paragraph). As noted above, the testing of 

the kiln exhaust diverted to the coal mill would be conducted upstream of the coal mill for THC 

and HCl so that only the kiln exhaust contribution is assessed. 

To monitor compliance continuously, we are proposing that gas flow rate from the coal mill and 

alkali bypass be monitored continuously and that a parametric limit for gas flow be established 

during the annual performance test. This flow rate measured during the annual performance test 

would be the maximum flow rate allowed during the year. If a higher flow rate is observed, the 

owner/operator would have to retest THC and HCl to obtain a new flow-weighted concentration 
10

which would be summed with the kiln main stack THC or HCl concentration to determine 

whether the kiln is still in compliance. Because of this requirement, the owner/operator should 

perform their test at a flow rate that would cover the range of conditions expected. For HCl, the 

performance test would be performed using Method 321 in Appendix A to 40 CFR Part 63. For 

measurement of THC, Method 25A in Appendix A-7 to 40 CFR Part 60 would be required.

Annual cost of a single test would be $20,000 per kiln for HCl and $8,000 for THC. Annual cost 

if tests are done on coal mill and alkali bypass stacks would be $40,000 and $16,000 for HCl and 

THC, respectively. The number of kilns with separate stacks that would have to be tested is not 

known. If it is assumed that one-half of the 133 kilns would require the test, total nationwide cost 

would be $2.7 million per year (40000*67) for HCl and $1.1 million per year (16000*67) for 

THC.

c. PM. As explained above, in the situation where a cement kiln diverts some exhaust to 

an integrated coal mill, the coal mill would have to meet the subpart Y standards, and the kiln 

would have to meet the subpart LLL NESHAP standard but would not have to account for the 

diverted exhaust in doing so. In all other situations, PM contribution from a coal mill (or from 

an alkali bypass) would be accounted for via the equation discussed in section 7 below. If the 

alkali bypass discharges separately, it would have to sum its PM emissions with those from the 

main stack and the summed emissions would have to be less than or equal to the subpart LLL 

NESHAP standard for PM. Allowing Sources With Dry Caustic Scrubbers to Comply With HCl 

Standard Using Performance Tests.

The September 2010 final rule allows sources equipped with wet scrubbers to comply with the 

HCl standard by means of periodic performance tests rather than with continuous monitoring of 

HCl with a CEMS. Sources electing to comply by means of stack tests must establish 

continuously monitored parameters including liquid flow rate, pressure and pH and are required 

to perform an initial compliance test using Method 321 and to test every 30 months thereafter.

Industry indicated that this compliance option should not be limited to wet scrubber equipped 

units, but should also be available for units equipped with dry caustic scrubbers, in part because 

some sources will be equipped with dry scrubbers (due to water shortages) and should have the 

same operating flexibilities as wet scrubber equipped kilns.

A recent review of data from a vendor of acid gas controls using a standard hydrated lime and a 

high performance hydrated lime at a US cement manufacturing plant, revealed that HCl removal 

from dry scrubbers on kilns ranged from 90 to 95 percent HCl removal, depending on lime 

injection rates (Lhoist North America, Cement Industry Experience, DSI for Acid Gas Control, 

October 5, 2011). The results also showed the plant could meet the 3 ppm HCl limit. EPA also 

evaluated HCl removal efficiency using dry sprayer absorber with a fabric filter as part of the 

electric utility generating (EGU) MACT rulemaking. Removal efficiencies ranged from 95 

percent to nearly 100 percent with an average of about 99.8 percent (Hutson to Nizich, HCl 

control using SDA/FF, November 29, 2011). In addition, information from the National Lime 

Association (http://www.lime.org/uses_of_lime/environmental/flue_gas.asp) and the Institute for 

Clean Air Companies (http://www.icac.com/i4a/pages/index.cfm?pageid=3401)report HCl 

emissions reductions using dry lime injection technology of 95 to 99 percent from coal-fired 

boilers in the electric utility industry, from municipal waste-to-energy facilities and from other 

industries. In the secondary aluminum industry, reductions in HCl emissions greater than 99 
11

percent have been achieved (National Lime Association, Flue Gas Desulfurization, 

http://www.lime.org/uses_of_lime/environmental/flue_gas.asp). 

Given these high reported removal efficiencies, we propose to extend the same option provided 

to kilns equipped with wet scrubbers to dry scrubber-equipped kilns. EPA is proposing that dry

scrubber-equipped kilns have the same option as kilns equipped with wet scrubbers for 

complying with the HCl limit by means of an initial and periodic stack test rather than 

continuous compliance monitoring with a CEMS. The proposed amendment would require that 

the lime injection rate used during the performance test demonstrating compliance with the HCl 

limit be recorded and then continuously monitored between performance tests to show that the 

injection rate remains at or above the rate used during the performance test. The number of 

sources that are likely to select this alternative monitoring approach is not known and impacts 

were not estimated.

EPA is also proposing additional alternatives for kilns that are equipped with a dry or wet 

scrubber. Where either wet or dry scrubbers are used, we are proposing that an owner or operator 

would have the option of using sulfur dioxide (SO2) monitoring as a monitoring parameter. We 

are also proposing to reduce the frequency of stack testing for scrubber-equipped kilns using 

SO2 monitors for parametric monitoring. Under this alternative, SO2 would serve as an indicator 

of a scrubber’s performance and not as a direct indicator of HCl emissions. Kilns equipped with 

dry or wet scrubbers that choose to use SO2 monitoring would need to conduct an initial 

performance test for HCl while monitoring SO2 to establish an SO2 level that would indicate 

compliance with the HCl limit. EPA is proposing that a performance test be conducted again in 

five years, at which time the SO2 parameter could be reset. As alternatives to the required HCl 

CEMS monitoring requirement, impacts were not estimated.

5. PM Standard for Modified Sources Under the NSPS

Under the September 2010 final NESHAP, existing kilns are subject to the NESHAP PM limit. 

If the kiln undergoes modification, it would continue to be subject to NESHAP PM limit, but 

would now be subject as well to the NSPS limit for new sources. EPA believes that it is more 

appropriate for modified kilns to meet the NESHAP PM limit for existing sources and is 

proposing that existing kilns that are subject to the NESHAP existing source emissions limit 

would continue to be subject to that limit and not to the more stringent limit for new sources 

under the NSPS. EPA examined the cost that a modified kiln would incur if they had to reduce 

emissions to the NSPS level and the amount of PM reduction. For an existing kiln to reduce 

emissions from 0.04 to 0.01 lb/ton clinker, a reduction of 0.03 lb/ton, it was assumed that the 

reduction would be achieved by changing out baghouse bags every year rather than every 5 

years. For a 1.2 million ton/yr kiln, annual baghouse cost would increase by $0.4 million/yr. The 

reduction in PM emissions for this example kiln would be 18 tons/yr. Thus a kiln would realize a 

modest reduction in PM emissions at a cost of about $21,000 per ton of PM reduced (See 

Appendix G).

6. Alternative PM Limit

Some kilns combine kiln exhaust gas with exhaust gas from other unit operations, such as the 

clinker cooler. The September 2010 final rule sought to accommodate commingled flows from 

the kiln and clinker cooler by providing a site specific PM limit and an equation for calculating 
12

the limit. In its reconsideration petition, industry brought to EPA’s attention, that other flows, 

such as coal mill exhausts and alkali bypass exhaust flows in addition to the exhaust gas flow 

from the clinker cooler can be commingled as well. Without an allowance for these additional 

flows, the site specific PM limit is stricter than EPA intended (since the PM concentration will 

be divided by a lower number in the implementing equation), and penalizes the energy-saving 

practice of commingling these flows. Although the form of the equation is correct, the equation 

is not written to accommodate sources other than exhaust gases from the clinker cooler. EPA is, 

therefore, proposing the following revised equation corrected to includes exhaust gas flows for 

all sources that would potentially be combined into a single exhaust gas stream, including the 

kiln, alkali bypass, coal mill and clinker cooler:

PM alt = 0.006 x 1.65 x (Qk + Qc + Qab + Qcm)/(7000) 

Where: 

PM alt is the alternative PM emission limit for commingled sources. 

0.006 is the PM exhaust concentration (gr/dscf) equivalent to 0.070 lb per ton clinker where 

clinker cooler and kiln exhaust gas are not combined1. 

1.65 is the conversion factor of lb feed per lb clinker

Qk is the exhaust flow of the kiln (dscf/ton raw feed)

Qc is the exhaust flow of the clinker cooler (dscf/ton raw feed).

Qab is the exhaust flow of the alkali bypass (dscf/ton raw feed).

Qcm is the exhaust flow of the coal mill (dscf/ton raw feed).

7000 is the conversion factor for gr per lb.

If exhaust gases for any of the sources contained in the equation are not commingled and are 

exhausted through a separate stack, their value in the equation would be zero. The alternative PM 

equation for new sources is identical to the existing source equation except the PM exhaust 

concentration used in the equation is 0.002 grams per dry standard cubic foot, which is 

equivalent to the new source PM limit of 0.020 lb/ton clinker.

7. MACT Floor Development

Applying the definition of solid waste developed in the NHSM rule, EPA has determined that 23 

cement kilns in the database which EPA used to develop the 2010 final NESHAP are now 

identified as commercial incinerators. Even though applying the reclassified kiln designation for 

the 23 kilns would have resulted in slightly different existing source emission standards for 

mercury, THC and PM, EPA is not proposing to amend the existing source standards for 

mercury and THC. The reasons for this decision are presented in the preamble to the proposed 

 

1 Note that this figure would change correspondingly if the EPA were to amend the existing source PM standard. 

The same is true of the PM term in the new source equation.
13

rule. EPA is proposing to revise the existing and new source PM standards. Also as described 

above in section 3, the limit for the alternative organic HAP limit (with parametric monitoring of 

THC) is being amended to reflect the limits of detection in the available measurement 

technology. The derivation of the limit for the alternative organic HAP is described in section 

10.5 below. A summary of the amended NESHAP for existing sources is presented in Table 1.

Table 1: Summary of 2012 Proposed NESHAP for Existing Sources

Pollutant Unit of Measure

2010 Final 

NESHAP

2012 

Proposed 

NESHAP

Hydrogen Chloride ppmvd 3 3

Mercury lb/MM tons clinker 55 55

Particulate Matter lb/ ton clinker 0.04 0.07

Total Hydrocarbon ppmvd 24 24

Organic HAP ppmvd 9 12

With respect to new source standards, EPA does not believe that any reclassification and 

reanalysis is necessary under the court’s opinion. New source floors can be based on the 

performance of “the best controlled similar source,” as opposed to existing source floors which 

must reflect performance of sources “in the category or subcategory.” CAA section 112 (d) (3) 

and (d)(3)(A). The changes to the particulate matter (PM) and organic HAP (oHAP) standards 

are not related to removal of the 23 kilns identified as incinerators. These changes are discussed 

below in the applicable sections. A summary of the amended NESHAP for new sources is 

presented in Table 2. 

Table 2: Summary of 2012 Proposed NESHAP for New Sources

Pollutant Unit of Measure

2010 Final 

NESHAP 

2012 

Proposed 

NESHAP

Hydrogen Chloride ppmvd 3 3

Mercury lb/MM tons clinker 21 21

Particulate Matter lb/MM tons clinker 0.01 0.02

Total Hydrocarbon ppmvd 24 24

Organic HAP ppmvd 9 12

7.1 Hydrogen Chloride (HCl)

a. Existing Sources

The 2012 proposed HCl NESHAP for existing sources was developed by removing any kilns 

from the 2010 Final data set that were identified as commercial incinerators and adding in any

new kilns that now fall into the NESHAP pool (top 12 %). The 2012 proposed HCl NESHAP 
14

for existing sources was developed with this new pool of kilns using the UPL method with 

pooled variance. As shown in Appendix A, the 2012 result of the UPL analysis for existing 

sources is less than three times the representative method detection level. As was done in the 

2010 Final, EPA is proposing to retain the current limit (3ppmvd) developed as three times the 

highest method detection level.

b. New Sources

As shown in Appendix B, the best performing kiln used to set the HCl NEHSAP for new sources 

in the 2010 Final was not identified as a commercial incinerator, so the same kiln was used for 

this analysis. As such, there is no reason the new source standard would change.

7.2 Mercury (Hg)

a. Existing Sources

EPA calculated the 99th confidence UPL for Hg after removing kilns from the 2010 final data set 

that were identified as commercial incinerators and replacing them with cement kilns to create 

the pool of best performing 12 % of sources. The UPL for existing sources was developed with 

this new pool of kilns using the UPL method with pooled variance, corrected for temporal 

autocorrelation with intraquarry variability. This process was identical to that used in the 2010 

final rule with the exception of the kilns in the pool data set. Appendix C contains the 

calculations used to develop the 2012 proposed Hg NESHAP for existing sources (58 lb/MM 

tons clinker).

As discussed in the preamble to the proposed rule, EPA is not proposing to revise the mercury

limit for existing sources, proposing to adopt 55 lb/MM ton clinker as a beyond the floor 

standard. The EPA is proposing a beyond-the-floor standard of 55 lb/MM ton clinker produced, 

the level of the 2010 final standard. The only difference in cost between the floor level of 58 

lb/MM ton clinker and the proposed standard of 55 lb/MM ton clinker is the incremental cost of 

removing slightly more mercury. This is because the control equipment needed for mercury (an 

activated carbon injection [ACI] system) would not alter, would not need to be sized differently, 

and would need to perform on average, nearly identically at either a 55 lb/MM tons clinker or 58 

lb/MM tons clinker level. That is, in planning compliance, kilns would calibrate to achieve an 

average performance of 34.1 lb/MM tons clinker for a standard of 58 lb/MM tons clinker, and 

31.7 for a standard of 55 lb/MM tons clinker, which translates to an additional reduction of 2.4

lb/MM tons of clinker per year. This equates to an estimated 221 pounds of nationwide mercury

emissions per year. To estimate the additional cost of going beyond the floor, we assumed that 

the rate of carbon injection would be increased to increase the mercury removal rate. The 

additional cost would then be the increased usage of activated carbon. Under the 2010 rule, we 

based the cost of compliance in part on an activated carbon injection rate of 3 pounds per million 

ACFM. Cost for an ACI system were developed for the 2010 final rule using costs from the state 

of New Jersey and the OAQPS Cost Manual. See Docket items EPA-HQ-OAR-2002-0051-1891, 

1872, 3398 and 3457 for background information and an explanation of cost estimates. The 

mercury reduction of 2.4 lb/MM tons of clinker is a 7 percent reduction from the level needed for 

long term compliance and we initially considered that the amount of carbon injected might also 

only need to be increased by 7 percent, from 3 lb to 3.2 lb per million ACFM. However, to allow 

for variability of removal effectiveness, pollutant loading and other uncertainties, we estimated 
15

the additional cost using an injection rate of 4 lb/ million ACFM. To achieve this additional 

reduction, we estimated an additional cost of approximately $359,000 for the industry, to 

purchase additional carbon injection materials. This equates to a cost-effectiveness of $2,000/lb 

of mercury reduction per year (see Appendix P).

b. New Sources

With respect to new source standards, as shown in Appendix D, applying this same method to 

the new sources would produce a slightly less stringent UPL (and we include this calculation for 

purposes of information). As discussed in preamble, EPA does not believe that any

reclassification and reanalysis for new sources is necessary under the court’s opinion because 

new source floors can be based on the performance of “the best controlled similar source.” 

Therefore, EPA is proposing to retain the new source Hg NESHAP developed under the 2010 

Final (21 lb/MM tons clinker).

7.3 Particulate Matter (PM)

a. Existing Sources

The 2012 proposed PM NESHAP for existing sources was developed by removing any kilns 

from the 2010 final data set that were identified as commercial incinerators and adding in any 

cement kilns that now fall into the NESHAP pool (top 12 %). The 2012 proposed PM NESHAP 

for existing sources was developed with this new pool of kilns using the UPL method with 

pooled variance. This process was identical to that used in the 2010 final with the exception of 

the kilns in the pool data set. Finally, in applying the UPL equation, EPA used m = 3 to be 

consistent with the proposed requirement to determine compliance using a three run Method 5 

test rather than a 30 day rolling average. Appendix E contains the calculations used to develop 

the 2012 proposed PM NESHAP for existing sources (0.07 lb/MM tons clinker).

b. New Sources

The best performing kiln used to set the PM NEHSAP for new sources in the 2010 Final was not 

identified as a commercial incinerator, so the same kiln was used for this analysis. We are 

proposing a standard of 0.02 lb./MM tons clinker rather than the 2010 final rule level of 0.01 

lb/MM tons clinker because a 3-run test will be used to determine compliance rather than a 30-

day rolling average, the calculation of the UPL uses m = 3 rather than 30. Appendix F contains 

the calculations used to develop the 2012 proposed PM NESHAP for new sources (0.02 lb/MM 

tons clinker).

7.4 Total Hydrocarbon (THC)

a. Existing Sources

The THC data for the 2010 standard consist of CEMS data for 15 kilns. After removing the four 

CISWI kilns, nine kilns remain. Thus, the MACT floor kilns consisted of 12 percent of these 

nine kilns, or two kilns. The top two kilns were Suwannee and Holcim. When CISWI sources are 

removed from the database for the 2010 standards, the existing source floor for THC becomes 

more stringent from 24 parts per million by volume (ppmv) to 15 ppmv, and the new source 

standard would drop from 24 ppmv to 11 ppmv (see Appendix K). This change results from 
16

removing from the database a CISWI cement kiln (the Lehigh Union Bridge kiln) with the 

lowest daily average performance but with more associated variability than the other kilns.

However, notwithstanding this calculation, the EPA is not proposing to reduce the level of either 

the new source and or existing source THC standard.

b. New Sources

With respect to existing source standards, EPA does not believe that the existing floor level 

(11 ppmv) would be technically appropriate. It omits the variability of the similar source with the 

best average performance for THC (the Union Bridge kiln), and so may not be fully

representative of variability of best performing sources. If the variability of the Union Bridge 

kiln is included along with the variability of the two best performing cement kilns, and applied to 

the two best performing cement kilns’ performance, the floor would be 24 ppm, which EPA is 

proposing as a floor (see Appendix O).

The basis for the new source standard was explained in the 2010 final rule. See 75 FR at 54981. 

As a best controlled similar source, the new source standard can continue to be based on the 

performance of this kiln (the Lehigh Union Bridge kiln).

See the preamble to the proposed rule for more discussion of the proposed THC standards.

7.5 Organic HAP (oHAP)

a. Existing and New Sources

For the total oHAP emissions data, EPA applied the following procedure for determining a 

representative detection level (RDL) for test methods used in measuring oHAPs. EPA 

determined method detection capabilities for Method 320 and Method 18 as the most appropriate 

for the various compounds (e.g., Method 320 for aldehydes, Method 18 for arenes) emitted by

kilns. EPA determined for each of the oHAPs the expected method detection level for the 

respective method based on internal experience and method capabilities reported by testing 

companies. With these values, EPA identified the resulting mean of the method detection levels 

as the RDL because it is characteristic of accepted source emissions measurement performance. 

EPA summed the RDLs of each oHAP in the data set and adjusted for dilution and moisture, 

then multiplied by three. Appendix H contains the calculations used to develop the 2012 

proposed oHAP NESHAP for existing and new sources (12 ppmvd).

8. Impacts of Revised PM Standard

For PM, EPA is proposing to change the limit for existing sources from 0.04 lb/ton clinker to 

0.07 lb/ton clinker. The PM limit for new sources also would be changed to 0.02 lb/ton clinker 

from 0.01 lb/ton clinker. The standard would be measured on a 3-run basis rather than on a 30-

day basis with a CEMS (see the final paragraph of this section). The proposed changes in the 

PM standards, while not considered significant in absolute terms will result in a small increase in 

total nationwide emissions. As explained in the impacts analysis for the 2010 rule (see Docket 

item EPA-HQ-OAR-2002-0051-3438), emission reductions were estimated by comparing 

baseline emissions to the long-term average emissions of the MACT floor kilns. The average 

emissions, rather than the emissions limit, must be used because to comply with the limit all or 
17

most of the time, emissions need to be reduced to the average of the MACT floor kilns. Under 

the 2010 rule, the average PM emissions from the existing floor kilns was 0.02296 lb/ton clinker. 

Under the reconsideration, the average PM emissions of the existing floor kilns is 0.02655 lb/ton 

clinker (see Appendix E). This is an increase of 0.00359 lb/ton clinker over the 2010 rule. The 

average emissions for new kilns did not change, so there would be no change in emissions from 

new kilns. In the 2010 rule, total clinker production from existing kilns was 75,355,116 tons per 

year. With an increase in PM emissions under the proposed rule of 0.00359 lb/ton clinker 

compared to the 2010 rule, nationwide emissions of PM would increase by 135 tons per year 

(0.00359 x 75,355,116/2000). These calculations are not so precise as to reliably predict to the 

third decimal point to the right of zero, so this difference should be viewed as suggesting a 

directional difference in the standards.

Kiln type 2010 rule Proposed rule Increment

Emissions limit (lb/ton clinker Existing 0.04 (30-day

average with 

a CEMS)

0.07 

(3-run stack test)

NA

MACT average emissions for 

compliance (lb/ton clinker

Existing 0.02296 0.02655 0.00359

2010 baseline emissions (tons/yr) 10,326 10,326 NA

Nationwide emissions reduction 

(tons/yr)

Total 9,489 9,354 135

Although the final measures that the industry will take to implement the final standards will be

site specific and cannot be accurately estimated here, it is possible that the industry would now 

be able to use existing PM control devices with less extensive modification rather than planned 

under the 2010 standard or rather than replacing them. Compliance strategies for the other HAPs, 

all of which involve some element of PM control, also may be affected. Cost savings from these 

alternatives could be significant. For example, we have performed a case study from the data set 

used in the 2010 impacts analysis. In this case study, the 21 ESP-equipped kilns no longer need 

to install membrane bags on a downstream polishing FF, and one FF retains their standard fabric 

bags rather than replacing them with membrane bags. The difference in annual cost for PM

control under this case study and the more stringent 2010 scenario is $18.6 million in capital cost 

and annualized cost of $4.2 million (see Appendix M). EPA believes this case study is a 

reasonable type of bounding estimate. Under this comparison, the annual cost of compliance 

will be $4.2 million less than under the 2010 rule. Under this comparison, the additional cost of 

reducing PM emissions to the 2010 rule level would be approximately $31,000 per ton of PM 

($4.2 million/135 tons PM). Assuming that 1 percent of PM is HAP (Docket item EPA-HQOAR-2002-0051-3438), the cost effectiveness would be approximately $3,000,000 per ton of 

HAP .

Because there are several substantial issues associated with the use of PS 11 at low PM 

emissions concentrations and given the variable emissions characteristics expected from Portland 

cement kilns, the EPA is proposing to change the compliance basis for the PM standard from

CEMS-based to stack-test based (preamble section III.D discusses these issues in detail). That 

is, the performance test requirement for this proposed rule would be a annual three test run 
18

compliance test with the EPA Method 5. The proposed rule would continue to require use of PM 

CEMS equipment but, as explained below, that equipment would be used for continuous 

parametric monitoring instead of for compliance with the numerical PM emissions limit.

Because the same equipment would be used, the capital cost of the equipment for continuous 

parametric monitoring and CEMS are the same. However, because PS 11 requires at least 15 

Method 5 test runs, equivalent to five tests, as part of the PS 11 calibration requirements, there 

will be a considerable savings when compared to the proposed single Method 5 performance test. 

At $15,000 per year for a single Method 5 test, the proposed rule will cost $60,000 less for 

testing than would be required under the PS 11 requirements for five tests at a cost of $75,000At 

a savings of $60,000 per kiln, nationwide savings for 133 new and existing kilns, would be $7.98 

million per year.

9. Summary

A summary of the costs for the proposed amendments are summarized in Table 3. 

Table 3. Cost of Proposed Amendments

Proposed Amendment Capital Cost Annualized Cost

Emissions 

Reduction

Coal mill testing and monitoring 

(section 4)

Mercury

THC

HCl

Flow meter

Total

$4,794,520

$4,794,520

$3,055,200

$1,072,000

$2,680,000

$1,510,850

$8,318,050 0

Mercury beyond the floor (section 

7.2)

0 $359,000 180 lb

Revised PM standard (section 8) $18,640,106 

(savings)

$4,200,000 

(savings)

135 tons (emissions 

increase)

Replace PM CEMS with PM CPMS 

(section 8)

0 $7,980,000

(savings)

0

Total $13,845,586

(savings)

$3,503,000 135 tons (emissions 

increase)

.